title: Crystallographic evidence of an unusual, pentagon-shaped folding pattern in a circular aromatic pentamer.
abstract: Introduction of a continuous hydrogen-bonding network suppressed the conformational flexibility of an oligomeric backbone. Cyclization of a rigidified, suitably sized oligomer led to a circular aromatic pentamer. Its crystal structure determined by X-ray crystallography reveals a pseudo five-fold symmetric planarity in the solid state, which is quite unusual among all the previously described shape-persistent macrocycles and synthetic foldamers with biased conformations enforced by noncovalent forces.
authors.affiliation: Department of Chemistry and NUS MedChem Program of the Office of Life Sciences, National University of Singapore, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Qin
authors.forename: Xiuying
authors.initials: X
authors.lastname: Chen
authors.forename: Xiao
authors.initials: X
authors.lastname: Fang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Shu
authors.forename: Yeow Kwan
authors.initials: YK
authors.lastname: Yip
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Siyan
authors.initials: S
authors.lastname: Pan
authors.forename: Wei Qiang
authors.initials: WQ
authors.lastname: Ong
authors.forename: Changliang
authors.initials: C
authors.lastname: Ren
authors.forename: Haibin
authors.initials: H
authors.lastname: Su
authors.forename: Huaqiang
authors.initials: H
authors.lastname: Zeng
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009930:Organic Chemicals / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals